Means for controlling the operation of steam boilers



V. Z. CARACRISTI AND C. H. SMOOT.'

MEANS FOR CUNTROLLING THE OPERATION OF STEAM BOILERS.

APPLICATION ,FlLEID oc.1920.

1,437,719., .Patented Dec. 5, 1922.

2 SHEETS-SHEET l.

V. Z. CARACRISTI AND C. H. SII/IOOT.

MEANS FOR CONTROLLING THE OPEHATloN 0E STEAM BOILERS.

APPLICATION .FILED OCI-5,1920.

LQSYQ. Patented Dec. 5, 1922.

2 SHEETS-SHEET 2.

IMbIZoM/ww W Patented lDec. 5, 1922.

STATES PATENT OFFICE.

VIRGINIUS Z. CARACRISTI, 'OF BRONXVILLE, NEW YORK, AND CEARLES H. SMOOT, OF SOUTH ORANGE, JERSEY; SAID SMOOT ASSIGNOR TO BATEAU BATTU SMOOT ENGINEERING CORPORATION, 0F NEW `YORK, N. Y., A CORPORATION OF DELA- WARE.

MEANS FOR CONTROLLING THE OPERATION 0F STEAM BOILERS.

Application led October 5, 1920. Serial No. 414,901.

To all whom t may concern.'

Be it known that we, VmGINIUs Z. CARA- CRIsTI and CHARLES H. SMooT, both citizens ofthe United States, and residents of Bronxville, count-y of Westchester, and State of New York, and South Orange, county of Essex, and State of New Jersey, respectively, have invented certain new and useful Improvements in Means for Controlling the Operation of Steam Boilers.

This invention relates to an improved means for automatically regulating or controlling steam pressure in steam generating plants. Generally considered we propose by means of the present invention to sensitively control the operation of the steam exhaust nozzle of a. locomotive through the medium of a suitable mechanism which is instantly responsive to variations in the requisite variable predetermined pressures or vacuum at different points in order to maintain a maximum of operating efficiency with an economical consumption of fuel.

We have exemplified our proposed automatie steam pressure control means for locomotives in one practical mechanical embodiment wherein the adjustable element of the variable steam exhaust nozzle is operatively connected to a series of pressure responsive diaphragme located in individual pressurereceiving chambers. Each of these chambers is connected to different parts of the locomotive, as for instance to 'the fire box, the steam space of the boiler, the smoke box, the steam' exhaust pipe, etc., whereby the pressure creating medium at these several points is admitted to the respective chambers at one or the other sides of the diaphragm therein so as to move the exhaust valve element towards its open or closed position upon an increase or decrease of pressure as the case may be.

It is a fact well known to locomotive railway engineers that there is a considerable loss in the vacuum in the fire box due to the drop in pressure of the gases and products of combustion in their passage through the re tubes which is caused by frictional resistance incident to the contact of the gases with the walls of thetubes. In order to maintain'the required degree of vacuum in the lire box requisite for the conversion of the water into steam, it is therefore necessary to increase thedraft pressure through the smoke box to compensate for the pressure decrease dueto friction losseswhich would otherwise occur inthe passage of the gases through the fire tubes. Accordingly it is obvious that in such case the exhaust nozzle must be closed. On the other hand, when there is a decrease in pressure in the steam pressure space of the locomotive boiler, the exhaust nozzle must be closed to increase the velocity of steam emitted from the nozzle until the boiler pressure is increased to the desired degree. Again, an increase in the steam pressure in the boiler beyond a predetermined point operates to automatically open the exhaust nozzle and increase the area of the steam emission orifice, thereby decreasing the emission velocity and accordingly decreasing the vacuum pressure in the ire box.

It will therefore be seen that we aim by means of our present improvement to maintain a substantially constant predetermined steam pressure in the boiler by the utilizaltion of variable pressure infiueneespoperating upon a pressure responsive exhaust nozzle-controlling mechanism.

With the above and other objects in view, the invention consists in the improved means for automatically regulating or controlling the boiler steam pressure, as will be hereinafter more fully described, illustrated in the accompanying drawings and subsequently incorporated in the sub-joined claims.

In the drawings wherein we have illustrated a practical and satisfactory embodiment of the apparatus and in which similar reference characters designate corresponding parts throughout the several views.

Figure l is a fragmentary longitudinal section through a locomotive boiler fire box and smoke box, showing the latter equipped with a variable steam exhaust nozzle.

Figure 2 is a longitudinal section of one type which we may em loy for the l automatic operation of the ex aust nozzle.

Figure 3 is a diagram graphically -illustrating the decrease in vacuumv pressure in the smoke box due to gas friction in the fire tubes of the'locomotive.

of pressure responsive mechanism- Referring in detail to the drawings and more particularly to Figure 1 thereof, 5 generally designates the locomotive boiler having the steam space A and the fire box B. Fire tubes 6 connect the fire box of the boiler to the front end 7 of the locomotive in which the usual superheater is arranged above the fire tubes, and the damper 9 is provided to direct the products of combustion issuing from the fire tubes either upwardly against the superheater tubes or downwardly and into the smoke box C.

10 generally indicates an exhaust nozzle havinof a. variable outlet orifice controlled bv the adjustable valve element 11. The spe*- cific. construction of this exhaust nozzle constitutes no part of the present invention but we will preferably employ a variable exhaust nozzle of the construction shown and described in the co-pending application for patent of Virginius Z. Caracristi filed October 11, 1920, berial No. 416,234. rlhe usual blower tube 12 surrounds the exhaust nozzle and subserves its usual function of discharging the smoke and gases when the locomotive is not in operation. For the purposes of t-he present explanation it will suffice to state that the element 11 of the exhaust nozzle is actuated through the medium of a rock shaft 13 which is connected by an arm 14 to the rod or stem of the valve-element 11.

15 designates the outlet tube or pipe leading to the nozzle 10 from the cylinders of the engine.

Referring now to Figure 2 of the drawings, wherein we have illustrated a pressure responsive mechanism of a type suitable for our present purposes. 16 designates a piston, one end of which is piVotally connected through the medium of the link 17 to the end of an arm 18, the other end of said arm being rigidly fixed upon the rock shaft 13.- rlhe piston 16 is operatively connected at its other end to a'series of flexible pressure responsive diaphragms 19 which are xed upon the common rod 20. These diaphragms are respectively arranged in separate or individual chambers 21 and to each chamber and at each side of the diaphragm.l therein a pressure supply pipe'22 is connected. These pressure supply pipes receive the pressure medium from different parts of the locomotive, as from the points A, `B and. C and the point D belovs7 the damper 9 and the point E at the connection of the steam exhaust pipe with the exhaust nozzle 10, said pipes being in communication with the chambers a, b, c, d, e, respectively, while `the end chamber f at the left, of Fig. 2 is water into steam. The upper curved line F of the diagram in Figure 3 indicates the normal required vacuum curve, the fuel consumption being assumedas 15() pounds of coal per square foot of grate area per hour for the indicated vacuum range.

1n order to maintain this variable degree of vacuum in the fire box, there must be a predetermined draft pressure at C. How eve-r, in the passage of the gas and products of combustion through the lire tubes 6, there considerable resistance due to friction created by the contact of the gases with the walls of the tubes. Thus there is a drop in vacuum pressure in the fire box as indicated by the lower curve G in Figure 3, and coni sequently a decrease in steam pressure at A below that which it is desired to maintain. Upon a substantial decrease in vacuum pressure in the smoke box, which pressure is transmitted to one of the chambers 21 and acts against one side of the diaphragm there# in, such decrease in the pressure-influence on the diaphragm will cause an operation of the valve element 11 to the desired extent to sufiiciently decrease the area of the outlet orifice of the exhaust nozzle 10 so that the emission velocity is increased and the draft pressure at C correspondingly increased, whereby the movement of the gases through the fire tubes is accelerated, thus compensating for frictional resistance and maintaining the necessary vacuum in the fire box. This variable draft pressure which is re uired at C is indicated by the vertical line in Figure 3 and as soon as the requisite pressure at this point has been attained, the pressure influences from the point C and the point B acting against relatively opposite sides of the diaphragm balance eachother so,that the valve element 11 remains stationary and the nozzle orifice of a constant area. On the other hand, assuming that for some reason there is a drop or loss in steam pressure at A below the predetermined desired minimum pressure, this decrease in the pressure iniuence acting on one side of another of the diaphragms 19 will result in a closing of the exhaust nozzle so as to increase the emission velocity of steam therefrom until the steam pressure at A is again returned to the point necessary to balance the .pres-l sure from the point C or D acting against the opposite side of the-diaphragm. Also it will be apparent that upon the increase of draft pressure at D or an increase in the steam pressure at E, the exhaust nozzle orice controlling element 11 will be moved to its open position to reduce velocity at the emission orifice and thereby reduce the draft or prevent back pressure through the steam pipe 15.

't will ofcourse be understood that in practice the severall diaphragms 19 may be of relatively different degrees of fiexibility or size so that they will resist or vield to box, and the smoke box of the locomotive relatively different pressure influences as may be determined in accordance with the steam` draft or vacuum pressures which it is necessary to maintain in order to realize the highest degree of operating efficiency with the'least consumption of fuel. Inthis manner. therefore, it will be seen that notwithstanding pressure losses in the tire box dueto frictional resistance to the passage of the products of combustion through the fire tubes, we are enabled to maintain a predetermined though variable steam pressure in the steam space A of the boiler. This desirable result is produced through the automatic variation of the area of the emission orifice of the steam exhaust nozzle and the element of human error in the proper operation of the exhaust valve to control the steam exhaust blast is entirely eliminated.

From the foregoing description considered in connection with the accompanying drawings, the advantages of our improved method of automatically controlling steam pressure in locomotive boilers as well as the construction and manner of operation of the mechanical embodiment of the invention herein illustrated will be fully .and clearly understood. The present invention may be readily adapted and applied to present-day locomotives now in general use at comparatively7 small expense of installation and maintenance. It will be understood. however. that the apparatus above described for practically accomplishing the desired result, is purely illustrative and that this mechanism is obviously susceptible to numerous modifications as maybe necessitated in view of the exigencies encountered in individual applications of the invention.

Accordingly. we reserve the privilege of resorting to all legitimate changes in the form, proportion and relative arrangement of the several parts of such mechanism as may be fairly embodied within the spirit and scope of the invention as claimed.

We claim:

1. In combination with a locomotive having a variable exhaust nozzle, pressureresponsive means operatively connected to the movable element of the exhaustnozzle and to different sources of pressure in the locomotive to thereby automatically actuate the movable element of the exhaust nozzle and vary the emission area of the nozzle orifice in direct proportion to variations in pressure at the several pressure sources.

2. In combination with a locomotive having a variable exhaust nozzle, pressure-responsive means operatively connected to the movable element of the exhaust nozzle, and pressurevsupply connections between said means and the steam boiler space, the fire whereby the exhaust nozzle is automatically actuated upon variations in steam, vacuum, or draft pressures t0 proportionately vary the area of the emission orilice of the nozzle.

3. In combination with a locomotive having a variable exhaust nozzle. pressure-responsive means operatively connected to the movable element of the exhaust nozzle, and pressure supply connections betwe n said means and the fire box,` and the s oke box of the locomotive whereby the exhaust nozzle is automatically actuated upon variations in vacuum or draft pressures to proportionately vary the area of the emission orifice of the nozzle.

4. In combination with a locomotive having a variable exhaust nozzle, pressure-responsive means operatively connected to the movable element of the exhaust nozzle, and pressure supply connections between said latter means and the boiler steam space. the fire box, the smoke box and the exhaust nozzle supply pipe whereby the exhaust nozzle is automatically actuated upon variations in pressure to proportionately vary the emission area of the nozzle orifice.

5. In combination with a locomotive having draft inducing means. pressure responsive means operatively connected to said draft inducing means and responsive to variations in pressure in the boiler steam space, tire box and smoke box, of the locomotive to thereby automatically control the operation of said draft inducing means.

6. In combination with a locomotive having a variable exhaust nozzle, pressure responsive means operatively connected to the movable element of said nozzle and to the steam cylinder exhaust pipe therefor to thereby automatically actuate the exhaust nozzle` and vary the emission area of the nozzle orifice in direct proportion to the increase in steam pressure in the exhaust pipe wherebyr back pressure through the exhaust 'pipeI will be prevented.

7. In combination with a locomotive having a variable exhaust nozzle, pressure responsive means operable by the influence of pressure variations at diferent points in the steam enerating system of the locomotive, an means operatively connecting the pressure-responsive means to the exhaust nozzle includinga rock shaft and an operating connection between said rock shafty and the movable nozzle element whereby the emission area of the nozzle ori- -ice is automatically varied in direct proportion to such pressure variations.

8. In combination with a locomotive having a variable exhaust nozzle, pressure` responsive means operatively connected to said nozzle and responsive to variations in pressure in the boiler steam space, fire box. and smoke box of the locomotive to thereby automatically control the operation of said nozzle.

9. In combination with a steam generating plant having draft inducing means, pressure responsive means operatively connected to Said draft inducing means and to different sources of pressure in the steam generating plant to thereby automatically control the operation of said draft inducing means. 10

In testimony that We claim the foregoing as our invention, We have signed our names hereunder.

VIRGINIUS Z. CARACRISTI. CHARLES H. SMOOT. 

